Nuclear factor-κB (NF-κB) is a transcriptional factor that regulates the expression of important genes related to cell survival. Activation of NF-κB is central to inflammatory response because it regulates the expression of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α). TNF-α not only induces inflammation, but also acts as a survival factor for many cancers and can stimulate the production of angiogenic factors. TNF-α has been found in ovarian, breast, prostate, bladder, and colorectal cancer as well as in lymphomas and leukemias. The role of NF-κB in cancer has been further illuminated by research showing that NF-κB promotes tumorigenesis by suppressing apoptosis and stimulating cell proliferation. Haefner, B. (2002) “NF-κB: arresting a major culprit in cancer,” Drug Discovery Today, 7, 653-663. Because of the role of NF-κB in tumorigenesis and inflammation, NF-κB inhibitors may prove useful as anti-cancer and anti-inflammation therapeutic agents.
The primary form of NF-κB is retained in the cytoplasm of resting cells by IκB, an inhibitor of NF-κB. NF-κB is activated by stimulation of a cellular kinase complex known as IκB kinase (“IKK”) complex, comprising subunits IKKα, β, and γ. Upon stimulation by, for example, a toxin, a cytokine (such as TNF-α), or ionizing radiation, IKK phosphorylates IκB and triggers ubiquitination-dependent degradation through the proteasome pathway. With IκB destroyed, NF-κB is free to enter the nucleus and activate transcription. Hu, M. (2004) “IκB Kinase Promotes Tumorigenesis through Inhibition of Forkhead FOXO3a,” Cell, 117, 225-237. Haefner, B. (2002) “NF-κB: arresting a major culprit in cancer,” Drug Discovery Today, 7, 653-663.
Aberrant expression of IKK has been correlated with activation of NF-κB and, in turn, tumorigenesis and cell proliferation. High IKK levels may also promote tumorigenesis by negatively regulating other transcription factors, such as FOXO factors. Hu, M. (2004) “IκB Kinase Promotes Tumorigenesis through Inhibition of Forkhead FOXO3a,” Cell, 117, 225-237. Thus, inhibiting IKK may inhibit cell proliferation and tumorigenesis. Other anilino-pyrimidine derivatives have been shown to inhibit inappropriately high kinase activity. See, e.g., U.S. Pat. No. 6,048,866. However, there remains a need for agents that selectively inhibit kinase activity, including IKK. The present invention fulfills this need.